P1742: SYSTEMATIC LITERATURE REVIEW OF THE BURDEN OF ILLNESS AND OUTCOME ANALYSES OF PATIENTS WITH NON-TRANSFUSION DEPENDENT BETA-THALASSEMIA
Authors: Y. Aydinok, A. Yucel, S. Deshpande, S. Purushotham, M. Dixit, R. Raorane, O. Agbeleye, M. Glassberg
Journal: HemaSphere (2022)

Background: Beta-thalassemia is a hereditary blood disorder characterized by impaired red blood cell (RBC) production resulting in chronic anemia, which may lead to serious complications if untreated. Patients with non-transfusion dependent beta-thalassemia (NTDT) do not require regular, lifelong RBC transfusions for survival but may need occasional transfusions. Although NTDT implicates a less severe form of beta-thalassemia, morbidities in NTDT cause a substantial disease burden that negatively impacts health-related quality of life (HRQoL). Aims: To understand the clinical, epidemiologic, economic, and humanistic burden of illness in adult patients with NTDT. Methods: A systematic literature review (SLR) was conducted in June 2021 to identify articles on patients with NTDT, defined by beta-thalassemia intermedia status and frequency of RBC transfusions received. Search and screening followed the methodology of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Cochrane. Results: In total, 3294 records were reviewed, with 308 publications identified for full-text review. Of those, 39 publications met the eligibility criteria and were included in the final analyses (Figure). In the 25 studies that reported clinical outcomes, patients with NTDT experienced elevated serum ferritin (SF) levels and increased liver iron concentration (LIC) requiring iron chelation therapy. Baseline mean SF level in patients with NTDT ranged from 518 to 4314.06 ng/mL; baseline mean LIC ranged from 2.1 to 31.8 Fe/g. Twenty-four of 25 epidemiologic studies reported morbidity outcomes. Patients with NTDT reported high morbidity burden such as diabetes (prevalence across studies range, 1.4–44.0%), heart failure (2.1–6.7%), pulmonary hypertension (10.0–33%), hypothyroidism (1.4–83.3%), hypogonadism (1.4–83.3%), cholelithiasis (13.8–100.0%), osteoporosis (13.3–83.3%), osteopenia (11.0–83.3%), extramedullary hematopoiesis (0.6–40.0%), hepatosplenomegaly (20.0–37.7%), hepatitis C virus infection (0.3–55.0%), thrombosis (6.7–26.7%), and liver complications (7.5–32.1%). In the 5 studies that reported HRQoL, patients with NTDT had significantly worse HRQoL outcomes than patients with transfusion-dependent beta-thalassemia (TDT), as shown by mean Short Form-36 (SF-36) total scores (66.5 [standard deviation (SD) 16.1] NTDT vs 75.8 [SD 18.8] TDT; P=0.021). Mean data from the various scales of SF-36 indicated significantly worse outcomes in physical health (66.2 [SD 16.8] NTDT vs 77.1 [SD 18.1] TDT; P=0.008), mental health (47.4 [SD 8.4] NTDT vs 51.6 [SD 7.2] TDT; P=0.009), and general health domains (41.9 [SD 8.2] NTDT vs 46.3 [SD 10.0] TDT; P=0.018). A higher burden of anemia was associated with lower mean health state utility values in the NTDT population (low burden of anemia 0.79 [SD 0.34] vs high burden of anemia 0.63 [SD 0.4]). Image:Summary/Conclusion: This SLR demonstrated that patients with NTDT experience poor clinical and HRQoL outcomes and have significantly worse HRQoL than patients with TDT; however, the limited literature identified provide an incomplete picture. Future studies on the epidemiology, morbidity, mortality, and economic burden associated with NTDT are needed to understand the clinical and economic impact experienced by these patients and society.